Due to their small-size, multi-functionality, and/or low-cost characteristics, semiconductor devices are being esteemed as important elements in the electronic industry. Higher integration of data storing devices, such as semiconductor memory devices, should satisfy consumer demands for superior performance and inexpensive prices. In the case of semiconductor memory devices, increased integration is sought after because integration is an important factor in determining product prices. However, the high price of process equipment needed to increase the fineness of semiconductor patterns sets a practical limitation on increasing integration of semiconductor memory devices. Accordingly, a variety of studies on new technology for increasing integration density of a data storing device are being conducted.